Bodiless bone fusion device, apparatus and method

ABSTRACT

A bodiless bone fusion method, apparatus and device for insertion between bones that are to be fused together and/or in place of one or more of the bones, such as, for example, the vertebrae of a spinal column. The bodiless bone fusion device comprises one or more extendable plates, one or more extending blocks in communication with the extendable plates, one or more positioning elements for adjusting the extendable plates by manipulating the extending blocks, and one or more support panels for holding the positioning elements and guiding the extendable plates. The plates are able to be advantageously positioned in the confined space between the vertebrae to help brace the device until the bone has fused.

RELATED APPLICATIONS

This Application claims priority under 35 U.S.C. 119 (e) of theco-pending U.S. Provisional Application Ser. No. 61/794,789, filed Mar.15, 2013, and entitled BODILESS BONE FUSION DEVICE, APPARATUS ANDMETHOD” and the co-pending U.S. Provisional Application Ser. No.61/858,505, filed Jul. 25, 2013, and entitled BODILESS BONE FUSIONDEVICE, APPARATUS AND METHOD,” both of which are hereby incorporated byreference.

FIELD OF THE INVENTION

This invention relates generally to bone fusion devices. Morespecifically, the present invention relates to bodiless devices forfusing vertebrae of the spine or other bones.

BACKGROUND OF THE INVENTION

The spinal column is made up of vertebrae stacked on top of one another.Between the vertebrae are discs which are gel-like cushions that act asshock-absorbers and keep the spine flexible. Injury, disease, orexcessive pressure on the discs can cause degenerative disc disease orother disorders where the disc becomes thinner and allows the vertebraeto move closer together or become misaligned. Similarly, vertebrae areable to weaken due to impact or disease reducing their ability toproperly distribute forces on the spine. As a result, nerves may becomepinched, causing pain that radiates into other parts of the body, orinstability of the vertebrae may ensue.

One method for correcting disc and/or vertebrae-related disorders is toinsert a fusion cage as a replacement for and/or in between thevertebrae to act as a structural replacement for the deteriorated discand/or vertebrae. The fusion cage is typically a hollow metal deviceusually made of titanium. Once inserted, the fusion cage maintains theproper separation between the vertebrae to prevent nerves from beingpinched and provides structural stability to the spine. Also, the insideof the cage is filled with bone graft material which eventually fusespermanently with the adjacent vertebrae into a single unit. However, itis difficult to retain this bone graft material in the cage and in theproper positions to stimulate bone growth.

The use of fusion cages for fusion and stabilization of vertebrae in thespine is known in the prior art. U.S. Pat. No. 4,961,740 to Ray, et al.entitled, “V-Thread Fusion Cage and Method of Fusing a Bone Joint,”discloses a fusion cage with a threaded outer surface, where the crownof the thread is sharp and cuts into the bone. Perforations are providedin valleys between adjacent turns of the thread. The cage can be screwedinto a threaded bore provided in the bone structure at the surgical siteand then packed with bone chips which promote fusion.

U.S. Pat. No. 5,015,247 to Michelson entitled, “Threaded SpinalImplant,” discloses a fusion implant comprising a cylindrical memberhaving a series of threads on the exterior of the cylindrical member forengaging the vertebrae to maintain the implant in place and a pluralityof openings in the cylindrical surface.

U.S. Pat. No. 6,342,074 to Simpson entitled, “Anterior Lumbar UnderbodyFusion Implant and Method For Fusing Adjacent Vertebrae,” discloses aone-piece spinal fusion implant comprising a hollow body having anaccess passage for insertion of bone graft material into theintervertebral space after the implant has been affixed to adjacentvertebrae. The implant provides a pair of screw-receiving passages thatare oppositely inclined relative to a central plane. In one embodiment,the screw-receiving passages enable the head of an orthopaedic screw tobe retained entirely within the access passage.

U.S. Pat. No. 5,885,287 to Bagby entitled, “Self-tapping Interbody BoneImplant,” discloses a bone joining implant with a rigid, implantablebase body having an outer surface with at least one bone bed engagingportion configured for engaging between a pair of bone bodies to bejoined, wherein at least one spline is provided by the bone bed engagingportion, the spline being constructed and arranged to extend outwardlyof the body and having an undercut portion.

U.S. Pat. No. 6,582,467 to Teitelbaum et al. entitled,“Expandable FusionCage,” discloses an expandable fusion cage where the surfaces of thecage have multiple portions cut out of the metal to form sharp barbs. Asthe cage is expanded, the sharp barbs protrude into the subcortical boneof the vertebrae to secure the cage in place. The cage is filled withbone or bone matrix material.

U.S. Pat. No. 5,800,550 to Sertich entitled, “Interbody Fusion Cage,”discloses a prosthetic device which includes an inert generallyrectangularly shaped support body adapted to be seated on hard endplates of vertebrae. The support body has top and bottom faces. A firstpeg is movably mounted in a first aperture located in the support body,and the first aperture terminates at one of the top and bottom faces ofthe support body. Further, the first peg projects away from the one ofthe top and bottom faces and into an adjacent vertebra to secure thesupport body in place relative to the vertebra.

U.S. Pat. No. 6,436,140 to Liu et al. entitled, “Expandable InterbodyFusion Cage and Method for Insertion,” discloses an expandable hollowinterbody fusion device, wherein the body is divided into a number ofbranches connected to one another at a fixed end and separated at anexpandable end. The expandable cage may be inserted in its substantiallycylindrical form and may be expanded by movement of an expansion memberto establish lordosis of the spine. An expansion member interacts withthe interior surfaces of the device to maintain the cage in the expandedcondition and provide a large internal chamber for receiving bonein-growth material. These patents all disclose fusion cage devices thatcan be inserted between vertebrae of the spine in an invasive surgicalprocedure. Such an invasive surgical procedure requires a long recoveryperiod.

SUMMARY OF THE INVENTION

The present application is directed to a bodiless bone fusion method,apparatus and device for insertion between bones that are to be fusedtogether and/or in place of one or more of the bones, such as, forexample, the vertebrae of a spinal column. The bodiless bone fusiondevice comprises one or more extendable plates, one or more extendingblocks in communication with the extendable plates, one or morepositioning elements for adjusting the extendable plates by manipulatingthe extending blocks, and one or more support panels for holding thepositioning elements and guiding the extendable plates. The bodilessbone fusion device is able to be inserted between or replace thevertebrae by using a minimally invasive procedure. After the device hasbeen positioned between the vertebrae, and the positioning elements areable to be rotated to position the plates. In particular, the plates areable to be positioned by rotating the positioning elements causingextending blocks to move and push outwards against the plates as theextending blocks approach the ends of the bodiless bone fusion device.In some embodiments, a single plate is extended. Thus, the plates areable to be advantageously positioned in the confined space between thevertebrae to help brace the device until the bone has fused.

A first aspect is directed to a bodiless bone fusion device forinsertion into a desired location. The bodiless bone fusion devicecomprises an extending mechanism including one or more extending blocksmechanically coupled with a positioning element such that rotation ofthe positioning element causes the blocks to move with respect to thepositioning element and a pair of plates straddling the extendingmechanism and mechanically coupled with the extending blocks such thatwhen the extending blocks move with respect to the positioning element,the plates move along a path with respect to each other between aretracted position in which the plates are adjacent to each other to anextended positioned in which the plates are spread apart from eachother, wherein the plates are sized such that at least a portion of theperimeter of the plates about the path align with the outermostperimeter of the device about the path. In some embodiments, the platesare sized such that the entirety of the perimeter of the plates aboutthe path align with the outermost perimeter of the device about thepath. In some embodiments, the device further comprises one or morebiasing elements physically coupled with both of the plates andpositioned such that the biasing elements apply a force resisting themovement of the plates from the retracted position to the extendedposition. In some embodiments, the biasing elements have a shapeselected from the group consisting of a ring, a C-shape and aring-shaped coil. In some embodiments, the extending blocks eachcomprise an angled surface between a left side and a right side, whereinthe left sides of the blocks are aligned with a left face of the platesand the right sides of the blocks are aligned with a right face of theplates. In some embodiments, angled surface forms a continuous sheetbetween the left and right sides of the blocks in order to increase thesurface area of the angled surface. In some embodiments, the devicefurther comprises a locking mechanism coupled with the positioningelement and configured to physically bias the rotational orientation ofthe positioning element into one of a plurality of positions. In someembodiments, the locking mechanism comprises one or more stoppers eachhaving a bump and a dial having one or more dimples and coupled with thepositioning element such that the dial rotates with the positioningelement, wherein the bumps do not rotate with the dial and the stoppersare positioned adjacent to the dial such that, when aligned, one or moreof the bumps spring into one or more of the dimples. In someembodiments, the device further comprises one or more support panelscoupled with the locking mechanism and the extending mechanism, whereineach of the support panels are positioned within a panel aperture oneach of the plates such that as the plates move between the retractedand the extended positions the plates slide up or down the panels viathe panels apertures. In some embodiments, at least one of the supportpanels comprises a pair of grip tabs that protrude from the sides of thesupport panel into a pair of grip apertures formed by the plates whenthe plates are in the retracted position. A second aspect is directed toa method of implanting a bodiless bone fusion device into a desiredlocation. The method comprises inserting the bodiless bone fusion devicein the desired location, wherein the bodiless bone fusion devicecomprises an extending mechanism including one or more extending blocksmechanically coupled with a positioning element such that rotation ofthe positioning element causes the blocks to move with respect to thepositioning element and a pair of plates straddling the extendingmechanism and mechanically coupled with the extending blocks such thatwhen the extending blocks move with respect to the positioning element,the plates move along a path with respect to each other between aretracted position in which the plates are adjacent to each other to anextended positioned in which the plates are spread apart from eachother, wherein the plates are sized such that at least a portion of theperimeter of the plates about the path align with the outermostperimeter of the device about the path and moving the plates between theretracted position and the extended position with the extendingmechanism. In some embodiments, the plates are sized such that theentirety of the perimeter of the plates about the path align with theoutermost perimeter of the device about the path. In some embodiments,the bodiless bone fusion device further comprises one or more biasingelements physically coupled with both of the plates and positioned suchthat the biasing elements apply a force resisting the movement of theplates from the retracted position to the extended position. In someembodiments, the biasing elements have a shape selected from the groupconsisting of a ring, a C-shape and a ring-shaped coil. In someembodiments, the extending blocks each comprise an angled surfacebetween a left side and a right side, wherein the left sides of theblocks are aligned with a left face of the plates and the right sides ofthe blocks are aligned with a right face of the plates. In someembodiments, the angled surface forms a continuous sheet between theleft and right sides of the blocks in order to increase the surface areaof the angled surface. In some embodiments, the bodiless bone fusiondevice further comprises a locking mechanism coupled with thepositioning element and configured to physically bias the rotationalorientation of the positioning element into one of a plurality ofpositions. In some embodiments, the locking mechanism comprises one ormore stoppers each having a bump and a dial having one or more dimplesand coupled with the positioning element such that the dial rotates withthe positioning element, wherein the bumps do not rotate with the dialand the stoppers are positioned adjacent to the dial such that, whenaligned, one or more of the bumps spring into one or more of thedimples. In some embodiments, the bodiless bone fusion device furthercomprises one or more support panels coupled with the locking mechanismand the extending mechanism, wherein each of the support panels arepositioned within a panel aperture on each of the plates such that asthe plates move between the retracted and the extended positions theplates slide up or down the panels via the panels apertures. In someembodiments, at least one of the support panels comprises a pair of griptabs that protrude from the sides of the support panel into a pair ofgrip apertures formed by the plates when the plates are in the retractedposition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a retracted perspective view of a bodiless bonefusion device according to some embodiments.

FIG. 1B illustrates an extended perspective view of a bodiless bonefusion device according to some embodiments.

FIG. 2 illustrates a cross-sectional view of components of the bodilessbone fusion device according to some embodiments.

FIG. 3A illustrates a profile view of the bodiless bone fusion devicewith the plates retracted according to some embodiments.

FIG. 3B illustrates a profile view of the bodiless bone fusion devicewith the plates extended according to some embodiments.

FIG. 4 illustrates a bodiless bone fusion device having a positionlocking mechanism according to some embodiments.

FIG. 5 illustrates a flow chart of a method of using the bodiless bonefusion device according to some embodiments.

FIG. 6A illustrates a front view of the bodiless bone fusion devicehaving a loop biasing element according to some embodiments.

FIG. 6B illustrates a front view of the bodiless bone fusion devicehaving a C shape biasing element according to some embodiments.

FIG. 6C illustrates a front view of the bodiless bone fusion devicehaving a garter spring biasing element according to some embodiments.

FIG. 7 illustrates a side up-close view of a positioning element andstopper according to some embodiments.

FIG. 8 illustrates a close-up view of support panels having retentiontips according to some embodiments.

FIG. 9A illustrates a retracted perspective view of a bodiless bonefusion device having stretched extending blocks according to someembodiments.

FIG. 9B illustrates an extended perspective view of a bodiless bonefusion device having stretched extending blocks according to someembodiments.

DETAILED DESCRIPTION

In the following description, numerous details and alternatives are setforth for purpose of explanation. However, one of ordinary skill in theart will realize that the invention can be practiced without the use ofthese specific details. For instance, the figures and description belowoften refer to the vertebral bones of a spinal column. However, one ofordinary skill in the art will recognize that some embodiments of theinvention are practiced for the fusion of other bones, including brokenbones and/or joints. In other instances, well-known structures anddevices are shown in block diagram form in order not to obscure thedescription of the invention with unnecessary detail.

FIGS. 1A and 1B illustrate retracted and extended perspective views,respectively, of a bodiless bone fusion device 100 according to someembodiments. The bodiless bone fusion device 100 is able to beconstructed from a high strength biocompatible material, such astitanium, which has the strength to withstand compressive and shearforces in the spine that are generated by a patient's body weight anddaily movements. Alternatively, part of all of the bodiless bone fusiondevice 100 is able to be constructed from one or more of the groupconsisting of high strength biocompatible material or a polymer such asPEEK, PEKK, and other polymeric materials know to be biocompatible andhaving sufficient strength. In some embodiments, the materials used toconstruct the bodiless bone fusion device include using additives, suchas carbon fibers for better performance of the materials under variouscircumstances. The base biocompatible material is often textured orcoated with a porous material conducive to the growth of new bone cellson the bodiless bone fusion device 100.

The bodiless bone fusion device 100 is able to have several conduits orholes 120 which permit the bone graft material to be inserted into thedevice 100 and to contact the vertebral bone before or after the device100 has been inserted between the vertebrae of the patient. Inparticular, one or more holes 120 are able to be positioned on thelateral faces of the device 100 through one or both of the plates 102such that the bone graft material is able to be inserted into the openspaces within the device 100 when the device is in the contractedposition. It is understood that although only one conduit 120 on alateral face is shown in FIG. 1A, any number of conduits 120 on lateralfaces or other parts of the device 100 is contemplated. The bone graftmaterial and the surface texturing of the device 100 encourage thegrowth and fusion of bone from the neighboring vertebrae. The fusion andhealing process will result in the bodiless bone fusion device 100aiding in the bridging of the bone between the two adjacent vertebralbodies of the spine which eventually fuse together during the healingperiod. As shown in FIGS. 1A and 1B, the bodiless bone fusion device 100comprises one or more extendable plates 102, one or more support panels104, one or more extending blocks 106, one or more positioning elements108 and one or more biasing elements 110. The positioning element 108 isrotatably positioned within panel apertures 103 of the support panels104 and operably coupled with the one or more extending blocks 106. Thesupport panels 104 are slidably positioned within plate apertures 118 ofthe extendable plates 102 and within a grip channel 114 of theextendable plates 102 when the device 100 is in the retracted positionas shown in FIG. 1A. The biasing element 110 is positioned withinbiasing channels 112 on one or both ends of the extendable plates 102.In some embodiments, one or more of the holes 120, the grip channels114, the biasing elements 110 and/or biasing channels 112 are able to beomitted. In some embodiments, one or more additional components are ableto be added as are well known in the art. Additionally, it is noted thatalthough FIGS. 1A and 1B only show two plates 102, a single positioningelement 108, two extending blocks 106, two support panels 104 and twobiasing elements 110, any number of plates 102, positioning elements108, extending blocks 106, support panels 104 and/or biasing elements110 is contemplated.

The one or more extending blocks 106 each are able to comprise athreaded conduit 122 for operably coupling to the positioning elements108. In particular, as described below, the positioning elements 108 areable to comprise a plurality of threaded screws having differentdiameters wherein the threaded conduits 122 of the extending blocks 106are able to be configured to screw onto or otherwise engage with one ofthe threaded screws of the positioning elements 108. Alternatively, oneor more of the screws are able to have the same diameter. Further, eachof the extending blocks 106 are able to comprise angled upper and/orlower outer surfaces for contacting/engaging angled inner surfaces 123(see FIGS. 3A and 3B) of the extending plates 102. Specifically, theangled outer surfaces are able to be configured such that as the blocks106 move along the positioning element 108 the angles outer surfacespush against the angled inner surfaces 123 causing the plates 102 tomove outwards.

The support panels 104 are able to be sized/configured to slidably fitwithin one or more plate apertures 118 within the extendable plates 102.In some embodiments, one or more of the plate apertures 118 extendcompletely through the corresponding plate 102. Alternatively, one ormore of the plate aperture 118 are able to only extend partially throughthe corresponding plate 102. When in the retracted position, the top andbottom portions of the support panels 104 are able to be positionedfully within a plate aperture 118 of each of the extendable plates 102(e.g. such that the edge of the support panels 104 is substantiallyflush with the surface of the plates 102 if the plate aperture 118extends through the top of the plate 102). As the plates 102 areextended outward to the extended position, the plates 102 slide up thepanels 104, but the panels 104 remain at least partially within theplate apertures 118 even when in the fully extended position. In someembodiments, as shown in FIG. 8, the top and/or bottom of the panels 104comprise one or more retention tips 101 that bow out or otherwiseprotrude out from the top and/or bottom of the panels 104 in order toblock or mechanically stop the plates 102 from sliding off the top ofthe panels 104. For example, the retention tips 101 are able to extendout from the panels 104 and if the plates 102 slide up to the retentiontips on the panel 104, the tips 101 provide a biasing force that pushesthe plates 102 back down the panels 104 until they no longer contact theretention tips 101. Alternatively, other types of fasteners or stoppingmechanisms are able to be used to prevent the plates 102 from sliding ofthe panels 104 as are well known in the art.

As a result, the panels 104 are able to maintain the alignment of theplates 102 with each other and with the positioning element 108 andextending blocks 106. Also, as described above, the support panels 104are each able to comprise one of the panel apertures 103 such that thepanels 104 are able to receive one end of the positioning element 108.Specifically, the panel apertures 103 are able to be configured toreceive a non-threaded portion of an end of the positioning element 108such that the positioning element 108 is held in place relative to thesupport panels 104, but allowed to rotate within the panel apertures103. One or more of the support panels 104 are also able to comprise oneor more grip tabs 105 that extend out the sides of the support panels105. As described below, the grip tabs 105 are configured to fit withinthe grip channels 114 of the plates 102 and provide a gripping point toan insertion instrument used to insert and otherwise manipulate thedevice 100. In some embodiments, the grip tabs 105 comprise one or moreindentations, conduits and/or fasteners for receiving detachablycoupling with an insertion tool. For example, the grip tabs 105 are ableto be configured such that they create a profile that matches theprofile of the insertion tool such that the tool is able to securelygrip the device 100 via the grip tabs 105.

The extendable plates 102 are able to be located on opposite sides ofthe device 100 and face is opposite directions. Internally, the plates102 are able to have one or more angled inner surfaces 123 (see FIGS. 3Aand 3B) that have end thicknesses that are larger than their middlethicknesses such that the thickness of the angled surfaces 123 graduallyincreases while going from the middle to the ends of the plate 102.Alternatively, the angled inner surfaces 123 are able to be configuredsuch that they have end thicknesses that are smaller than their middlethicknesses such that the thickness of the angled surfaces 123 graduallydecreases while going from the middle to the ends of the plate 102. Ineither configuration, the angles surfaces 123 are able to interact withthe extending blocks 106 to cause the plates 102 to retract or extendbetween the retracted and extended positions. As described above, theplates 102 each comprise one or more plate apertures 118 that are sizedto slidably receive the top or bottom of the support panels 104. As aresult, the panels 104 are able to keep the plates 102 in alignment witheach other as the plate 102 slide up and down along the support panels104. Additionally, in some embodiments the panels 104 are able to beshaped similar to the grip tabs 105 and/or other shapes such that thepanels 104 are able to both support the plates 102 as well as enable theplates 102 to slide along the panels 104.

As also described above, the plates 102 each able to comprise the one ormore biasing channels 112. In particular, the biasing channels 112 areable to be configured such that when the device 100 is in the retractedposition the biasing channels 112 of the plates 102 align to form acontinuous channel that crosses between the plates 102. In someembodiments, the biasing channels 112 are able to align at two or morepositions between the plates 102 to form a continuous loop or othershape that crosses multiple times between the plates 102. In someembodiments, the biasing channels 112 include a lip guard 111 that holdsthe biasing elements 110 within the biasing channels 112. Alternatively,the biasing channels 112 are able to comprise coupling elements (notshown) that enable the biasing elements 110 to directly couple to thebiasing channels 112 in order to stay within the channels 112. Althoughas shown in FIG. 2 the lip guard 111 is substantially straight forming asquare-like channel 112, it is contemplated that the guard 111 is ableto be angled, rounded, indented or otherwise shaped such that the guard111 is able to retain the biasing elements 110 within the biasingchannels 112. Further, the biasing channels 112 are able to each includeone or more portions that are nonparallel to the direction in which theplates 102 are able to be extended in order to fit a biasing element 110that provides resistence to the extension of and biases the plates 102in the retracted position. In some embodiments, as shown in FIGS. 1A and1B the biasing channels 112 form a C shape. Alternatively, the biasingchannels 112 are able to form a loop (see FIGS. 6A-6C), snake or othershapes having nonparallel portions as are well known in the art.Alternatively, the biasing channels 112 are able to be entirely parallelbut be coupled to the biasing element 110 such that a nonparallelportion is unnecessary to provide the force resisting extension of theplates 102. In some embodiments, the biasing channels 112 are positionedon the ends of the plates 102 as shown in FIGS. 1A and 1B.Alternatively, one or more of the biasing channels 112 are able to bepositioned on another lateral face or faces of the plates 102.

Additionally, the plates 102 are able to have serrated edges or teeth136 to further increase the bodiless bone fusion device's grippingability and therefore ability to be secured in place between the bonesfor both a long-term purchase and a short-term purchase. In someembodiments, the serrated edges or teeth 136 are able to be in atriangular or form a triangular wave formation as shown in FIG. 2.Alternatively, the serrated edges or teeth are able to be filleted,chamfered, or comprise other teeth shapes or edge waves as are wellknown in the art. As described above, the plates 102 are able tocomprise the grip channels 114 positioned on opposite sides of one ormore ends of the plates 102. The grip channels 114 are able to beconfigured such that when the device 100 is in the retracted positionthe grip channels 114 of the plates 102 align and are partially filledby grip tabs 105 of the support panels 105. The remainder of the gripchannels 114 is able to be configured to receive gripping fingers of aninsertion instrument (not shown). In particular, the grip channels 114enable the insertion instrument to grip the grip tabs 105 of one of thesupport panels 104 to manipulate the device 100 and to prevent thedevice 100 from slipping or during insertion into a patient.Alternatively, the grip tabs 105 are able to comprise one or more screwholes or other types of fasteners for fastening to an insertioninstrument as are well known in the art.

Finally, the plates 102 are able to be configured such that when in theretracted position the extendable plates 102 house or surround theremainder of the components of the device 100. As a result, the bodilessbone fusion device 100 provides the advantage of maximizing the platesize to device size ratio because the size of the plates 102 is equal tothe size of the device 100 in the retracted position creating a 1 to 1ratio. This enables the device 100 to incorporate larger plates 102 thatincrease stability and surface area, which would not be possible withdevices that incorporate a body. Additionally, it should be noted thatone or more of the plates 102 are able to be non-flat, non-parallel toeach other, or otherwise non-uniform. For example, one or more of theplates 102 are able to be partially or fully concave, convex and/orangled. Further, in some embodiments one or more of the plates 102 areable to be adjustable or interchangeable such that they enableadjustments to their surface/body shape.

The positioning element 108 is able to comprise a positioning aperture109, a first screw 107A and a second screw 107B coupled together (seeFIG. 2). The positioning aperture 109 is configured to receive adrive/engaging mechanism of a tool (not shown) such that the tool isable to rotate the positioning element 108. The positioning aperture 109is able to comprise numerous shapes and sizes as are well known in theart. Alternatively, the positioning aperture 109 is able to be omittedand/or the end of the positioning element 108 is able to be shaped tofit within the drive/engaging mechanism of the tool. The first screw107A is threaded opposite of the second screw 107B. For example, if thefirst screw 107A is left threaded, the second screw 107B is rightthreaded or vice versa. Furthermore, the first screw 107A is of aslightly different size than the second screw 107B. As described above,the positioning element 108 is able to be operably coupled to one ormore of the extending blocks 106. For example, a first one of theextending blocks 106 is able to be threaded onto the first screw 107Aand a second one of the extending blocks 106 is able to be threaded onto the second screw 107B.

When coupled to the positioning element 108, the extending blocks 102are able to be positioned in the middle of the bodiless bone fusiondevice 100 in the retracted position. When the positioning element 108is turned appropriately, the extending blocks 106 each travel outwardlyon their respective screws 107A and 107B. As the extending blocks 106travel outwardly, they push the angles surfaces 123 of the plates 102causing the plates 102 to extend outward along the support panels 104.In other words, the inner plate surface 123 when in contact with theextending blocks 106 act in such a manner so as to push the respectiveplates 102 apart. Thus, the plates 102 will be fully extended when theextending blocks 106 reach the opposite ends of the screws 107A, 107B.To retract the plates 102, the positioning device 108 is turned in theopposite direction and the extending blocks 106 will each travel back tothe middle on their respective screws 107A and 107B. It is contemplatedthat the operation of the device 100 is able to be reversed such thatthe plates 102, extending blocks 106, and positioning element 108 areconfigured such that the extending blocks 106 travel inwardly to extendthe plates 102 into the extended position and travel outwardly toretract the plates 102 into the compact position. In any case, thenonextended plates 102 of the bodiless bone fusion device 100 provide acompact assembly that is suitable for insertion into the patient's bodythrough a open, or minimally invasive surgical procedure. As usedherein, an open or a minimally invasive procedure comprises a procedurewherein a smaller surgical incision is employed as compared to the sizeof the incision required for conventional invasive surgery, for examplearthroscopic procedures. Moreover, minimally invasive proceduresminimize or eliminate the need for excessive retraction of a patient'stissues such as muscles and nerves, thereby minimizing trauma and injuryto the muscles and nerves and further reducing the patient's recoverytime. The biasing elements 110 are able to be configured to fit withinthe biasing channels 112 of two or more plates 102 when the plates 102are in alignment. For example, as shown in FIGS. 1A, 1B and 6B, one ormore of the biasing elements 110 are able to shaped in a C shape orbroken loop shape. Alternatively, as shown in FIG. 6A, one or more ofthe biasing elements 110 are able to have a circular, oval or loopshape. Alternatively, as shown in FIG. 6C, one or more of the biasingelements 110 are able to have a garter spring shape or any other type ofshape formed by the biasing channels 112. Further, the biasing element110 are able to be shaped to fit behind the lip guard 111 such that thelip guard 111 holds the biasing element 110 in place within the biasingchannels 112. Alternatively, the biasing element 110 is able to directlycouple to the plates 102 in order to stay within the biasing channels112. In some embodiments, the biasing elements 110 are able to bestructured and/or positioned such that their body blocks the extensionof the plates 102 and thus the extension of the plates 102 causesdeformation and/or stretching of the body of the biasing elements 110.As a result, the body deformation and/or stretching resistence of thebiasing elements 100 provides an extension-resisting force that biasesthe plates 102 in the retracted position. This biasing provides theadvantage of ensuring that the plates 102 remain in contact withextending blocks 106 as the plates 102 are extended and/or retracted. Insome embodiments, one or more of the biasing elements 110 comprisenitinol to provide the deformation resistant and/or flexible structure.Alternatively, the biasing elements 110 are able to comprise othermaterial having deformation resistant, springing and/or elasticproperties as are well known in the art.

FIG. 2 illustrates a cross-sectional view of components of the bodilessbone fusion device 100 according to some embodiments. As shown in FIG. 2and described above, the positioning element 108 is able to comprise afirst screw 107A and a second screw 107B wherein the first screw 107A isthreaded differently than that of the second screw 107B and is adifferent size than the second screw 107B. For example, in someembodiments the first screw 107A is an 8-32 screw and the second screwis a 6-32 screw. A first extending block 106A and a second extendingblock 106B are utilized with the positioning element 108 to extend andretract one or more of the plates 107A with respect to each other and/orthe positioning element 108. The first extending block 106A has aninternal opening and threading to fit around the first screw 107A. Thesecond extending block 106B has an internal opening and threading to fitaround the second screw 107B. The support panels 104 are coupled withthe positioning element 108 via the plate apertures 118 of the plates102. Specifically, because the plate apertures 118 receive the ends ofthe support panels 104, they prevent the panel apertures 103 of thesupport panels 104 from moving axially with respect to the positioningelement 108 thereby keeping the ends of the positioning element 108within the panel apertures 103. Further, the plates 102 are each coupledwith each other via the support panels 104 that maintain the alignmentof the plates 102 and the biasing elements 110 that hold the plates 102onto the support panels 104. FIG. 3A illustrates a profile view of thebodiless bone fusion device 100 with the plates 102 retracted accordingto some embodiments. When the extending blocks 106 are positioned in themiddle of the positioning element 108 with the first screw 107A and thesecond screw 107B, the plates 102 are positioned adjacent and/or incontact with each other. FIG. 3B illustrates a profile view of thebodiless bone fusion device 100 with the plates 102 extended accordingto some embodiments. As shown in FIG. 3A, the bodiless bone fusiondevice 100 is compressed/retracted when the extending blocks 106 are inthe middle of the bodiless bone fusion device 100. As a user rotates thepositioning element 108 via the positioning aperture 109, the extendingblocks 106 gradually move outward from the middle. If the user turns thepositioning element 108 in the opposite direction, the extending blocksmove back towards the middle. As the extending blocks 106 are movingoutward, the extending blocks 106A, 106B push on inner angles surfaces123 of the plates 102. The plates 102 extend because the extendingblocks 106 exert force against the angled inner surfaces 123 of theplates 102 outwardly as shown by the arrows 140. When the extendingblocks 106 are positioned near the ends of the bodiless bone fusiondevice 100, the plates 102 extend beyond the outer edges of the ends ofthe support panels 104 of the bodiless bone fusion device 100 andultimately secure the bodiless bone fusion device 100 between two bones.In operation, the bodiless bone fusion device 100 is initiallyconfigured in a compact position such that the extending blocks 106A,106B are located in the middle of the bodiless bone fusion device 100thereby allowing the plates 102 to contact each other and/or the edgesof the ends of the support panels 104 to be substantially flush with theouter surfaces of the plates 102 through the plate apertures 118. Thecompact bodiless bone fusion device 100 is then inserted into positionwithin the patient and surgeon is able to expand the bodiless bonefusion device 100 by rotating the positioning element 108 which movesthe extending blocks 106A, 106B towards the opposing ends of thebodiless bone fusion device 100—one near the head of the positioningelement 108 and the other towards the tail of the positioning element108. As the extending blocks 106A, 106B move away from the middle, theplates 102 are pushed outwardly from the pressure of the extendingblocks 106A, 106B against the angled inner surfaces 123.

Eventually the extending blocks 106A, 106B exert a satisfactory forcebetween the extended plates 102 and the bones to be fused. At that pointthe bodiless bone fusion device 100 is able to remain in place. If theplates 102 are extended too far, the surgeon is able to rotate thepositioning element 108 in the opposite direction moving the extendingblocks 106A, 106B back towards the middle. At the same time, the biasingelements 110 exert a retraction force in the opposite direction of theforce 140 that ensures the plates 102 retract as the extending blocks106A, 106B move back towards the middle of the device 100. Inparticular, the retraction force is able to be applied to the plates 102by biasing elements 110 throughout operation of the device 100 in orderto both keep the plates 102 from sliding off the support panels 104 andkeep the plates 102 in contact with the extending blocks 106 as theblocks 106 move along the positioning element 108. Thereafter, materialfor fusing the bones together is inserted through the holes and openings120 within the bodiless bone fusion device 100. Alternatively, theinsertion of the material for fusing the bones together is able to beomitted.

FIG. 4 illustrates a bodiless bone fusion device 400 having a positionlocking mechanism 402 according to some embodiments. The bodiless bonefusion device 400 shown in FIG. 4 is substantially similar to thebodiless bone fusion device 100 except for the differences describedherein. It is noted that the plates 102 of the bone fusion device 400have been omitted from FIG. 4 for the sake of clarity. As shown in FIG.4, at least one of the support panels 104 comprises one or moreadditional panel apertures 99 configured to receive a position lockingmechanism 402, wherein the position locking mechanism 402 comprises oneor more dials 404 and one or more stoppers 406. The dial 404 isconfigured to rotatably fit within the panel apertures 99 and comprisesa dial aperture 412 and one or more dimples 410 along the edge orperimeter of the dial 202. The dial aperture 412 is able to be sized orotherwise configured to receive an end of the positioning element 108such that if the positioning element 108 is within the dial aperture412, the end of the positioning element 108 will cause the dial 404 torotate along with the positioning element 108. In some embodiments, thepositioning element 108 causes the dial 404 to rotate by directlyphysically contacting the dial aperture 412.

Alternatively, the positioning element 108 is able to cause the dial 404to rotate via indirect contact. The one or more dimples 410 are able tobe configured to receive one or more bumps 408 of the stoppers 406. Inparticular, the dimples 410 are able to have concave dimensions thatsubstantially match convex dimensions of the bumps 408. The stoppers 406are able to be configured to fit within the panel apertures 99 adjacentto the dial 404 and comprise one or more bumps 408. The stoppers 406,dials 404 and apertures 99 are configured such that when within theapertures 99, the stoppers 406 are adjacent or in contact with the dial404 and the bumps 408 of the stoppers 406 snap or spring fit within thedimples 410 of the dial 404 when a dimple 410 and a bump 408 arealigned. Additionally, when a dimple 410 and a bump 408 are not aligned,the bump 408 is compressed against the dimple-less edge of the dial 404and primed to spring or decompress into a dimple 410 when alignment isachieved.

In some embodiments, the dial 404 is held in place within the additionalpanel apertures 99 by force applied by the bumps 408 of the stoppers406. For example, in some embodiments the dimples 410 are able to beconcave and centered along the perimeter of the dial 404 such that whenthe bumps 408 are within the dimples 410 the outer walls of theconcavity of the dimples 410 prevents the dial 404 and/or the stoppers406 from falling out of place. As another example, as shown in FIG. 7the dial 404 is able to be omitted or incorporated into the positioningelement 108, wherein the perimeter of the positioning element 108 thatis adjacent the stoppers 406 forms a trough or channel 401 that receivesthe stoppers 406 such that the positioning element 108 is unable to comeout of position with respect to the stoppers 406. In such embodiments,the bottom of the trough is able to comprise the dimples 410 forreceiving the bumps 408 of the stoppers 406. Alternatively, the dial 404is able to be otherwise coupled or uncoupled within the apertures 99 byone or more fastening elements as are well known in the art.

In some embodiments, the stoppers 406 are held in place within theadditional panel apertures 99 by place holders 407. In particular, theplace holders 407 are able to be tensioned and/or compressed by the wallof the apertures 99 when the stoppers 406 are inserted into theapertures 99 and thus provide a spring force against the walls of theapertures 99 to try and relieve that tensioning/compression.Accordingly, the spring force holds the stoppers 406 within theapertures 99. Alternatively, one or more of the stoppers 406 are able tobe otherwise coupled or uncoupled within the apertures 99 by one or morefastening elements as are well known in the art. Although as shown inFIG. 4, the device 400 comprises one of the panels 104 including theposition locking mechanism 402, wherein the position locking mechanism402 comprises a single dial 404 having sixteen dimples 410 and twostoppers 406, it is understood that any number of the panels 104 areable to include a position locking mechanism 402 and the positionlocking mechanism is able to include any number of dials 404 having anynumber of dimples 410 coupled to any number of stoppers 406. In someembodiments, the additional panel apertures 99 are able to replace thepanel aperture 103 and/or the dial aperture 410 is able to besubstantially similar to the panel aperture 103 in size and shape.

In operation, as the positioning element 108 is rotated to extend orretract the plates 102, the dial 404 is rotated along with thepositioning element 108 and the bumps 408 compress and decompress intoand out of the dimples 410 as they move in an out of alignment with thebumps 408. As a result, each point during the rotation of thepositioning element 108 that results in an alignment of a bump 408 and adimple 410 serves as a demarcated degree of rotation and/or degree ofextension/retraction of the plates 102. In this way, the positionlocking mechanism 402 provides the advantage of enabling a user torotate the positioning element 108 and thereby extend the plates 102 topredetermined rotation/extension amounts and/or by predeterminedrotation/extension intervals represented by the spacing and number ofdimple 410 and bump 408 alignment points. For example, the positionand/or number of dimples 410 and/or bumps 408 of the position lockingmechanism 402 is able to be adjusted to adjust the number and/orposition of the alignment points and therefore the number and/orposition of plate extension points. Thus, the position locking mechanism402 of the bodiless bone fusion device 400 is able to be tuned todifferent size devices 400 based on the number of extension incrementsneeded and the desired extension distance interval between each of theincrements. In some embodiments, the increments are configured to beconstant. Alternatively, the increments are able to be configured todecrease in size as the plates 102 approach the maximum extension level.Alternatively, other increment profiles are able to be used as are wellknown in the art. Further, the compression of the bumps 408 and theirresistance thereto during rotation of the positioning element 108between alignment points provides a slipping resistance force theresists unintended rotation of the positioning element 108 out of analignment point. As a result, the position locking mechanism 402provides the advantage of reducing the chance of the positioning element108 unintentionally rotating and/or the plates 102 unintentionallyextending or retracting.

FIG. 5 illustrates a flow chart of a method of using a bodiless bonefusion device according to some embodiments. A user pre-configures theone or more plates 102 of the bodiless bone fusion device to theretracted position with the positioning element 108 and the one or moreextending blocks 106 such that the device has a minimized form factor atthe step 502. The user inserts the bodiless bone fusion device into adesired position in between the bones at the step 504. The user extendsthe plates 102 to a desired extension level between the bones byrotating the positioning element 108 causing the extending blocks 106 topush the plates 102 outward to the desired extension level at the step506. In some embodiments, the rotating of the positioning element 108comprises rotating the positioning element 108 through a number ofalignment points of the position locking mechanism 402 until a desiredalignment point is reached. As a result, the method is able to providethe benefits of a minimally invasive surgery due to the minimized formfactor of the bodiless bone fusion device in the retracted position anda more accurate and stable extension point due to the position lockingmechanism. FIGS. 9A and 9B illustrate a retracted perspective view andan extended perspective view of a bodiless bone fusion device 900 havingstretched or expanded extending blocks according to some embodiments.The bodiless bone fusion device 900 shown in FIGS. 9A and 9B issubstantially similar to the bodiless bone fusion device 100 except forthe differences described herein. Specifically, the sides 902 of theextending blocks 106 shown in FIGS. 9A and 9B extend such that the sides902 substantially align with the outer surface of the device 900.

As a result, the extending blocks 106 span the entire width of theplates 102 which creates greater surface area for the blocks 106 tocontact the plates 102 as well as greater stability in the extendedposition as a wider portion of the plates 102 is directlycontacted/supported by the blocks 106. In such embodiments, the skirt orsides 904 of the plates 102 are able to comprise a block cavity 906configured to receive the sides 902 of the blocks 106 when the device900 is in the retracted position. Although as shown in FIGS. 9A and 9B,both sides 902 of both blocks 106 are expanded to align with theexterior surface of the sides 904 of the plates 102, one or more of thesides 902 of one or more of the blocks 106 are able to not be expandedand/or be expanded less. For example, one of the sides 902 of one of theblocks 106 is able to extend part way into the cavity 906 on one of thesides 904 of the plates 102.

Thus, the bodiless bone fusion device, apparatus and method describedherein has numerous advantages. Specifically, the bodiless bone fusiondevice provides the advantage of maximizing the plate size to devicesize ratio because the size of the plates is equal to the size of thedevice in the retracted position creating a 1 to 1 ratio. This enablesthe device to incorporate larger plates that increase stability andsurface area, which would not be possible with devices that incorporatea body. Also, the device provides the advantage of the grip channelsthat ensure the non-slippage of the driving mechanism during theoperation of the bone fusion apparatus.

Further, the position locking mechanism provides the advantage ofreducing the chance of the positioning element unintentionally rotatingand/or the plates unintentionally extending or retracting. Also, asmentioned above, the method of use requires only a small incision andminimally invasive surgical procedure advantageously promoting healthand rapid recovery by the patient. Indeed, bone growth occurs around thebodiless bone fusion device and particularly at the locations of theextended plates, such that the bodiless bone fusion device is furthersecured by the bone growth, which further promotes a superior, robustbone fusion result. Moreover, the device provides the advantage ofextending blocks that span the entire width of the plates therebycreating greater surface area for the blocks to contact the plates aswell as providing greater stability in the extended position as a widerportion of the plates is directly contacted/supported by the blocks.

The present invention has been described in terms of specificembodiments incorporating details to facilitate the understanding ofprinciples of construction and operation of the invention. Suchreference herein to specific embodiments and details thereof is notintended to limit the scope of the claims appended hereto. It will beapparent to those skilled in the art that modification may be made inthe embodiments chosen for illustration without departing from thespirit and scope of the invention. For example, it should be noted thatalthough the above bodiless bone fusion devices are described inreference to a pair of extending blocks, a pair of screws, and whereineach plate is shaped such that the ends are larger than the middle, andthe size of the plate gradually increases while going from the middle tothe ends, the use of a single extending block in the above embodimentsis contemplated. Specifically, if using a single extending block, theabove embodiments would operate the same except the positioning elementwould comprise a single screw that when engaged would cause the singleextending block to move from one end of the screw to the other endthereby exerting a force against the plates such that they move into theextended position. In such embodiments, each plate is shaped such thatone end is larger than the opposite end, and the size of the plategradually increases going from the smaller end to the larger end.

What is claimed is:
 1. A bodiless bone fusion device for insertion intoa desired location comprising: an extending mechanism including one ormore extending blocks mechanically coupled with a positioning elementsuch that rotation of the positioning element causes the blocks to movewith respect to the positioning element; and a pair of plates straddlingthe extending mechanism and mechanically coupled with the extendingblocks such that when the extending blocks move with respect to thepositioning element, the plates move along a path with respect to eachother between a retracted position in which the plates are adjacent toeach other to an extended positioned in which the plates are spreadapart from each other, wherein the plates are sized such that at least aportion of the perimeter of the plates about the path align with theoutermost perimeter of the device about the path.
 2. The device of claim1, wherein the plates are sized such that the entirety of the perimeterof the plates about the path align with the outermost perimeter of thedevice about the path.
 3. The device of claim 1, further comprising oneor more biasing elements physically coupled with both of the plates andpositioned such that the biasing elements apply a force resisting themovement of the plates from the retracted position to the extendedposition.
 4. The device of claim 3, wherein the biasing elements have ashape selected from the group consisting of a ring, a C-shape and aring-shaped coil.
 5. The device of claim 1, wherein the extending blockseach comprise an angled surface between a left side and a right side,wherein the left sides of the blocks are aligned with a left face of theplates and the right sides of the blocks are aligned with a right faceof the plates.
 6. The device of claim 5, wherein the angled surfaceforms a continuous sheet between the left and right sides of the blocksin order to increase the surface area of the angled surface.
 7. Thedevice of claim 1, further comprising a locking mechanism coupled withthe positioning element and configured to physically bias the rotationalorientation of the positioning element into one of a plurality ofpositions.
 8. The device of claim 7, wherein the locking mechanismcomprises one or more stoppers each having a bump and a dial having oneor more dimples and coupled with the positioning element such that thedial rotates with the positioning element, wherein the bumps do notrotate with the dial and the stoppers are positioned adjacent to thedial such that, when aligned, one or more of the bumps spring into oneor more of the dimples.
 9. The device of claim 8, further comprising oneor more support panels coupled with the locking mechanism and theextending mechanism, wherein each of the support panels are positionedwithin a panel aperture on each of the plates such that as the platesmove between the retracted and the extended positions the plates slideup or down the panels via the panels apertures.
 10. The device of claim9, wherein at least one of the support panels comprises a pair of griptabs that protrude from the sides of the support panel into a pair ofgrip apertures formed by the plates when the plates are in the retractedposition.
 11. A method of implanting a bodiless bone fusion device intoa desired location, the method comprising: inserting the bodiless bonefusion device in the desired location, wherein the bodiless bone fusiondevice comprises: an extending mechanism including one or more extendingblocks mechanically coupled with a positioning element such thatrotation of the positioning element causes the blocks to move withrespect to the positioning element; and a pair of plates straddling theextending mechanism and mechanically coupled with the extending blockssuch that when the extending blocks move with respect to the positioningelement, the plates move along a path with respect to each other betweena retracted position in which the plates are adjacent to each other toan extended positioned in which the plates are spread apart from eachother, wherein the plates are sized such that at least a portion of theperimeter of the plates about the path align with the outermostperimeter of the device about the path; and moving the plates betweenthe retracted position and the extended position with the extendingmechanism.
 12. The method of claim 11, wherein the plates are sized suchthat the entirety of the perimeter of the plates about the path alignwith the outermost perimeter of the device about the path.
 13. Themethod of claim 11, wherein the bodiless bone fusion device furthercomprises one or more biasing elements physically coupled with both ofthe plates and positioned such that the biasing elements apply a forceresisting the movement of the plates from the retracted position to theextended position.
 14. The method of claim 13, wherein the biasingelements have a shape selected from the group consisting of a ring, aC-shape and a ring-shaped coil.
 15. The method of claim 11, wherein theextending blocks each comprise an angled surface between a left side anda right side, wherein the left sides of the blocks are aligned with aleft face of the plates and the right sides of the blocks are alignedwith a right face of the plates.
 16. The method of claim 15, wherein theangled surface forms a continuous sheet between the left and right sidesof the blocks in order to increase the surface area of the angledsurface.
 17. The method of claim 11, wherein the bodiless bone fusiondevice further comprises a locking mechanism coupled with thepositioning element and configured to physically bias the rotationalorientation of the positioning element into one of a plurality ofpositions.
 18. The method of claim 17, wherein the locking mechanismcomprises one or more stoppers each having a bump and a dial having oneor more dimples and coupled with the positioning element such that thedial rotates with the positioning element, wherein the bumps do notrotate with the dial and the stoppers are positioned adjacent to thedial such that, when aligned, one or more of the bumps spring into oneor more of the dimples.
 19. The method of claim 18, wherein the bodilessbone fusion device further comprises one or more support panels coupledwith the locking mechanism and the extending mechanism, wherein each ofthe support panels are positioned within a panel aperture on each of theplates such that as the plates move between the retracted and theextended positions the plates slide up or down the panels via the panelsapertures.
 20. The method of claim 19, wherein at least one of thesupport panels comprises a pair of grip tabs that protrude from thesides of the support panel into a pair of grip apertures formed by theplates when the plates are in the retracted position.